JPH05333213

• Main Authors: NISHIURA YOSUKE, SHIRATO KENTARO, TODA SATORU, YAMANOUCHI JUNICHI
• Format: Patent
• Language: English
• Published: 17.12.1993
• Edition: 5
• Subjects: DEVICES OR ARRANGEMENTS, THE OPTICAL OPERATION OF WHICH ISMODIFIED BY CHANGING THE OPTICAL PROPERTIES OF THE MEDIUM OF THEDEVICES OR ARRANGEMENTS FOR THE CONTROL OF THE INTENSITY,COLOUR, PHASE, POLARISATION OR DIRECTION OF LIGHT, e.g.SWITCHING, GATING, MODULATING OR DEMODULATING; FREQUENCY-CHANGING; NON-LINEAR OPTICS; OPTICAL ANALOGUE/DIGITAL CONVERTERS; OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICAL LOGIC ELEMENTS; OPTICS; PHYSICS; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF

PURPOSE:To enable the inexpensive production of the film with good efficiency by using a specific styrene copolymer, thereby ameliorating the brittleness and easy tendency to cracking of the film and lessening the change in double refractive value by heat. CONSTITUTION:This film is a uniaxially stretched styrene copolymer film and contains a graft polymer prepd. by addition polymerizing >=1 kinds of monomers contg. at least styrene monomers with a polymer having unsatd. double bonds in the main chain or side chains. In addition, the graft polymer is produced by a suspension polymn. in an aq. medium and has negative intrinsic double refractions. The polymer having at least the unsatd. double bonds in the main chain or side chains has a repeating unit derived from a monomer having a conjugated diene structure and its glass transition temp. is <=30 deg.C. Further, the monomer to be addition polymerized consists of at least one kind of the styrene monomers and acrylinitrile or methacrylinitrile.